Alloys at the Nanoscale; The Case of Nanoparticles

贵金属纳米粒子在现代纳米技术中有着广泛的应用。事实上，从催化到医学，从光学到磁性，许多应用都在文献中有所描述。然而，对它们的性质的理解还远远没有完全实现。例如，Au/Pd已被发现是一种极好的加氢催化剂，其活性远远优于这两种金属。此外，当金存在时，催化剂变得耐硫中毒。然而，对这些影响仍缺乏清晰的认识。该项目启动了一个两国合作的项目，旨在了解双金属纳米颗粒的结构和行为。该项目由美国德克萨斯大学奥斯汀分校、新莱昂大学（UANL）、波托西科学调查研究所（IPYCIT）和墨西哥圣路易斯波托西自治大学（IFUASLP）共同开展。目的是利用分子动力学、先进的透射电镜和受控合成技术，清楚地识别双金属颗粒优异性能的来源。合金Au-Pd， Au-Ag, Pt-Au, Pt-Ag， Pd-Ag和Pd-Pt是特别感兴趣的。样品将在两国制备并交换表征。分子动力学计算将在墨西哥实验室使用德克萨斯大学奥斯汀分校的超级计算机进行，电子显微镜和其他表征将在德克萨斯大学奥斯汀分校进行。该项目将为在墨西哥实验室学习的美国学生提供国际经验。此外，访问德克萨斯大学奥斯汀分校的墨西哥学生将与美国少数民族本科生建立联系，并为这些学生提供榜样。预计这项工作的基础科学成果将有助于为氢燃料时代开发更好的催化剂。该奖项由美国国家科学基金会国际科学与工程办公室共同资助。

Nanoparticles of noble metals are widely used in modern nanotechnology. Indeed, many applications ranging from catalysis to medical, from optical to magnetic have been described in the literature. The understanding, however, of their properties is far from fully achieved. For instance, Au/Pd has being found to be an excellent hydrogenation catalyst with activity far superior to either metal. Also when gold is present the catalyst becomes resistant to sulfur poisoning. Yet, a clear understanding of these effects is still missing. This project launches a bi-national effort to understand the structure and behavior of bimetallic nanoparticles. The project is conducted by the University of Texas at Austin in the US, and the University of Nuevo Leon (UANL), the Instituto Potosino de Investigacion Cientifica (IPYCIT), and the Universidad Autonoma de San Luis Potosi (IFUASLP) in Mexico.The aim is to clearly identify, using molecular dynamics, advanced TEM and controlled synthesis, the origin of the outstanding properties of bimetallic particles. The alloys Au-Pd, Au-Ag, Pt-Au, Pt-Ag, Pd-Ag, and Pd-Pt are of special interest. Samples will be prepared in both countries and exchanged for characterization. The molecular dynamics calculations will be performed in the Mexican labs using the supercomputer at UT-Austin, electron microscopy and other characterization will be performed in UT-Austin. The project will provide international experiences to US students who will spend time in the Mexican laboratories. In addition, Mexican students visiting UT-Austin will be linked with US minority undergraduates and provide role models for those students. It is expected that fundamental science outcomes from this effort will assist the development of better catalysts for a hydrogen-fuel era.This award is co-funded by the NSF Office of International Science and Engineering.